Boom reach and angle indexing indicator



C. M. TOWNE BOOM REACH AND ANGLE INDEXING INDICATOR Feb. 25, 1964 2 Sheets-Sheet 1 Filed Jan. 24, 1962 mm W. km v z & @w

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Feb. 25, 1964 c. M. TOWNE 3,122,125

BOOM REACH AND ANGLE INDEXING INDICATOR Filed Jan. 24, 1962 2 Sheets-Sheet 2 United States Patent 3,122,125 BOOM REACH AND ANGLE IYDEXING INDICATOR Claude M. Towne, Watertown, Wis., assignor to Village Blacksmith Corporation, a corporation of Delaware Filed Jan. 24, 1962, Ser. No. 168,350 12 Claims. (Cl. 116--124) This invention relates to a boom reach and angle indicator for pivoted booms of construction, excavating and the like, machinery.

Many cranes have relatively long booms and are used in construction of buildings and other civil engineering projects where the operator of the crane cannot always visually observe the position of the load at the end of his boom. It has been proposed in the past that there be devices for indicating the angle of the boom to horizontal, such indication being made at the convenient location adjacent the operator in the cab of the crane. This information is helpful but not sufiicient for most crane operators. A very important additional bit of information would be the distance from the pivot pin of the boom to the vertically hanging load line at the end of the boom. The distance varies as the cosine of the angle that the boom occupies with relation to horizontal. Some devices have been devised for giving such a reading of reach distance for a single boom. The devices have not been adaptable, however, to actual working conditions because boom lengths are often changed on a job site.

It is the principal object of this invention to provide a new and improved boom reach and angle indicator adaptable for use in practically all known boom-equipped machinery.

Another object is to provide such an indicator which can constantly indicate the distancefrom the horizontal boom pin to a position vertically below the outer end of the boom, such distance being commonly called reac Another object is to provide an indicator which automatically indicates the angle of the boom to horizontal for the particular length of boom on the machine in which it is installed.

Another object is to provide an indicator which is read: ily adaptable for use with a boom shortened by removal of a section, lengthened by the addition of a section, or changed in effective length by the addition or subtraction of a gooseneck or a jib.

A further object is to provide a novel system of indication of boom reach giving smaller graduations of indi cation of boom movement in the area of boom movement where a few degrees of angle change greatly affects the reach of the boom.

Other objects, features and advantages of the present invention will be apparent from the following description of a perferred embodiment illustrated in the accompanying drawings, in which:

FIGURE 1 is a fragmentary front elevational view of the indicatingdrum and associated parts of the subject invention;

FIGURE 2 is a central vertical sectional view through the drum and associated parts taken substantially along line 22 in FIGURE 1;

FIGURE 3 is a fragmentary side elevational view partially broken away showing a typical installation of the indicator in the cab and boom of anexcavating machine; FIGURE 4 is a fragmentary enlarged sectional view of the means for holding the dials stationary'relative to i the drum;

. FIGURE 5 is a diagrammatic front elevational view of the dials of the indicator in one position; and

FIGURE 6 is a view similar to FIGURES of the dials in another position. I

ICE

2 Referring particularly to FIGURES 1 and 3, the present indicator is usually attached to the boom and installed 7 in the cab of the machinery for the convenience of the operator. In FIGURE 3 the cab 10 of an excavating machine with the window 11, through which the operator may view his control of the machine, is shown. A crane type boom 12 is pivoted to the base of the machine on a large horizontal boom pin 13 and may be raised and low ered generally between a horizontal and upright position. The position and reach indicator of this invention is provided with a cable drive connecting the boom and the instrument in the cab. Preferably, the outer end of the cable 14 is attached to a quadrant 15 having an arcuate surface attached to the boomsin a position to have its centeron the center of the boom pin. The quadrant is supported and attached to a base 16 provided with means for attachment thereof to the boom 12. In some excavating machines the operator may sit on the left hand side and in others his position may be slightly different. The controls from the cab to other parts of the machinery vary so that it may be desirable to attach the indicator of this invention on either the left or the right hand side of the boom. For this purpose the quadrant 15 may be mounted sinistrally or dextrally with relation to the support 16 to provide for avoidance of accessories and the like at the foot of the boom. In any event, the cable drive so attached to the boom may be made to pass over a pair of pulleys 17 and 18 in order to reach the indicating instrument 20 attached to the inside of the cab 10.

The face of'the instrument 20 is shown in FIGURE 1 and it will be noted that a base plate 21 is provided with openings 22 suitable for mounting the instrument on a wall of the cab. A drum 23 is rotatable on the base past a stationary indicator wire 24. The drum is spring loaded against the pull of the cable 14 and, therefore, will rotate in proportion to the swinging of the boom about its horizontal pivot. The ratio of such movement is preferably one complete rotation of the drum through 360 for swinging ofthe boom from a horizontal to a vertical position approximating In this connection the outer peripheral degree carrying surface 25 of the drum is marked off in degrees beginning at 0 and ending at 90, the latter position being under the stationary datum wire 24. Other dials spaced inwardly from the peripheral degree markings include a plurality of win dows such as 26 arranged in a spiral pattern in order to make visible indicia on an underlying dial. The indicia which appear in the windows are the reach distances which the particular boom will have when the window passes under the stationary datum wire 24. The specific example illustrated in FIGURE 1 is for a boom of feet in length so that the 150 indicia appears in the window 26 directly under the datum wire and beside the legend Set boom length here, which is printed on the face of the outer dial. The indicia appearing in the other windows 26 are values less than 15 0 feetand indicate the reach of the 150 foot boom as it is raised from the hori- In the movement of'a boom from horizontal to vertical position, the reach does not vary as a straight line function of the angle change. Since the reach is the (.9 distance between the boom pivot and a vertical line dropped from the outer end of the boom, quite obviously, the reach varies rapidly when the boom is more nearly upright and less rapidly as the boom travels nearly its horizontal position. It may be noted in FIGURE 1 that the larger boom lengths are on the outer end of the spiral path in which the windows 26 are arranged. On the inner end of the spiral indicia 51 and 26 appearing in the windows indicate a relatively rapid change in reach for a change in the angle of the boom between 70 and 80 to horizontal. It is contemplated within this invention to reverse the position of the spiral so that the outer extent of the spiral positioned windows will record the reaches of the boom when it is more nearly upright. Such structure is illustrated in FIGURES 5 and 6 in more detail.

The structure of the indicator of this invention is more nearly shown in FIGURES 2 and 4. The base plate 21 has a stationary shaft or spindle attached thereto by an appropriate fastener 31 and forming the support for the drum. The drum has an inner bearing 32 and an outer bearing formed of two concentric flanged bronze sleeves 33 and 34. The drum is made of sheet metal pressed upon the bearings and includes a back plate 35 pressed upon a rim -36 to form a round surface for the reception of a cable 14. The peripheral rim 37 extends over the front of the drum to form the degree carrying surface 25. Appropriate frame members 38 are secured to the drum parts and the front plate 39 of the drum is secured 'to the frame and press-fitted on to the outer bearing 33. A relatively large coil spring 40 in the nature of 'a clock spring is attached to the frame 38 and 'to the stationary spindle 30 to provide suflicient tension, maintaining the drum pulling against the cable 14 sufficiently to maintain the latter taut.

The front face of the drum, the front plate 39, provides only a support for the dials and has no indicia thereon. The dials are two in number, are round and rotatable with respect to the drum and with respect to each other. As shown in FIGURE 2, the innermost dial 41 is spaced from the front of the dial by a raised rib 39a on the front. The dial itself is superposed by an outer dial 42 but held frictionally in relation thereto by a plurality of corresponding deten'ts 43. Quite a number of detents 'are provided, as 'may be seen in FIGURE 1. Over both dials is a clear transparent plastic shade 44 having openings 45 therein to accommodate the detents 43. The dials and the plastic cover are confined between the flange "of the outer bronze sleeve 34 and the front of the drum so that they are somewhat resiliently held together and thus against movement relative to each other. The dials themselves are held against rotation as a unit relative to the front of the drum by a manually operable detent finger 46 at the bottom of the drum shown in detail in FIGURE 4. The detent finger is urged by a spring 47 toward the periphery of dial 41 and engages notches therein as illustrated. A knurled flange may be used to withdraw the detent from the notches provided in the periphery of the inner dial. The datum Wire 24 is supportedon a coil spring 47 attached to a top cantilever arm ii; secured to the base support. The inner end of the wire is attached to a ring 49 riding in the space between the flanges of the two bronze sleeves 33 and 34. The indicating fingers 27 and 28 are secured by friction washers against the end of the rotating bearing sleeves by a fastener 50.

Referring particularly to FIGURES 5 and 6, the dials 41 and 42 are shown diagrammatically in their superposed relationship. The indicia appearing in the windows 26 are those that are printed upon the face of the inner dial '41. In FIGURE 5 the uppermost window 26 has the number 70 appearing thereon. This corresponds to the length of the boom on the machine. If the boom moves 5 downwardly from a vertical position, the next window 26 to the ri ht will be under the datum wire 24, since the drum rotates. The indicia appearing in this window is 6 indicating that the reach of the boom at this point is 6 feet. It will be noted that the windows are on a spiral pattern and that 70 will again appear in the innermost window when the boom reaches its horizontal position stretching its total length outwardly. Additional windows and indicia may be provided in areas where reach changes rapidly with little boom angle change.

The inner dial is equipped with indicia which indicate the reach of six different boom lengths. As shown in FIGURE 5, a portion of the indicia on the inner dial are shown, thus there is included in dotted outline adjacent the periphery of the dials the numbers 30, 40, 50, 60, 70, and 80. These are in a position to appear in the uppermost window 26 when the outer and inner dials are rotated relative to each other. As a matter of convenience in permitting the manual rotation a number of knobs 55 (FIGURE 1) are provided on the outer dial so that it can be moved over the detents 43 relative to the inner dial and while the inner dial is held by the spring pressed finger 46 in a stationary position relative to the drum. The result of such a movement of the outer dial 42 relative to the inner dial is illustrated in FIGURE 6. Here, the windows have been moved so that the 40 foot length of boom and its reaches appear in the windows.

In order to clearly illustrate the provision of indicia in the inner dial 4-1, the line of indicia under the boom length is shown in FIGURE 5. The number 19 appearing in the Window is on the spiral pattern of windows and is for the 70 foot length of boom as indicated. The next inner number 30 would appear in the windows if the dials were rotated to bring the 60 foot boom length into registration with the windows. Theother numbers in the sequence correspondingly belong with the other boom lengths indicated. In general use, excavating machinery embraces boom lengths from 30 to 150 feet graduating such lengths in 10 foot intervals. On a job site, a crane operator very often may have to add or subtract a boom section thus varying the length of his boom. In addition, a jib or a gooseneck may he added to the end of the boom thus changing its effective length. In any such instance the operator need only adjust the outer dial relative to the inner so as to bring the adjustable length of his boom into the spirally placed windows. Thereafter, he need only withdraw the finger detent t6 and rotate both dials to place the proper reach length under the stationary datum. Thereafter, the rotation of the indicator drum will give the operator a simultaneous reading of the angle of his boom to horizontal and the reach of his boom in feet. In order to keep the dials to a relatively small size of about eight or nine inches in diameter, two inner dials 41 may be manufactured, one for boom lengths from 30 to 80 feet and another for lengths from to feet. Most machines will be adaptable to one or the other but not both dials.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as some modifications will be obvious to those skilled in the art.

I claim:

*1. An indicator for visibly indicating reach distance and angle of inclination of a pivoted boom in construction machinery and the like, comprising: a rotatable drum and a cable drive connecting the boom and drum to rotate the drum in proportion to swinging of the boom about its pivot; a mounting for the drum including a sta- 'tionary datum; degree indicia on the drum for indicating from 0 to 90 of boom swing from horizontal to vertical positions respectively; and superposed dials carried by said drum for rotation therewith, one dial having openings therein arranged on a spiral path and the other dial having indicia spaced to be exposed in said one dial openings in- '5 dicating the reach of the boom when the drum is turned responsive to boom swing to bring the exposed indicia adjacent the stationary datum.

2. An indicator as specified in claim 1 wherein, the superposed dials are rotatable Within the drum and manual lock means are provided for indexing the dials to a selected position within the drum to indicate reach of the particular boom length on the machinery.

3. An indicator as specified in claim 1 wherein each dial is rotatable relative to the other dial and frictional engaging means urge the dials against such relative rotation, said openings in said one dial being registrable with reach indicia on said other dial indicative of the reach of different lengths of boom.

4. An indicator as specified in claim 1 wherein said one dial has said openings arranged on a spiral extending through about 360 and said cable drive is arranged to move the larger radius portion of said spiral path past the stationary datum during movement of boom near its upright position.

5. A boom reach and angle indicator for a crane having a pivoted boom, comprising: a rotatable drum having means for mounting the same within the crane in view of an operator; a drive train for the drum connected with the boom forrotating the drum in proportion to swinging movement of the boom about its pivot; inner I and outer superposed dials carried by the drum, the inner dial havin indicia indicating the reach of the boom at different angles of repose relative to the ground, the outer dial having a series of openings therein arranged in a spiral pattern for exposing the indicia on the inner dial; and a stationary datum adjacent the drum and overlying said dials whereby the reach indicia maybe read when adjacent the datum. I

6. An indicating device for visibly indicating reach distance and angle of inclination of a pivoted boom in corn struction machinery and the like, comprising: a rotatable drum; a cable drive connecting the drum and a boom for rotating the drum in proportion to swinging ot the boom;

I arranged in spiral paths, each graduated in amounts to list reach of a boom of a different length, the other of said dials covering said indicia and having openings therein to expose one spiral path indicia at a time, and friction means for holding said dials together in selected relative position for rotation with said drum past said stationary datum. I

7. An indicating device as specified in claim 6 in which both of said dials are rotatable relative to said drums for indexing the indicia to a position relative to said stationary datum indicating boom reach for the boom on said construction machinery and manual releasable means secure said dials against movement relative to said drum.

8. An indicating device for visibly indicating reach distance and angle of inclination of a pivoted boom in construction machinery and the like, comprising: a rotatable'drum; a cable drive connecting the drum and a boom for rotatingthe drum in proportion to swinging of the boom; a stationary datum adjacent the periphery of the drum; degree indicia carried on the drum for swinging past the datum to indicate angleof the boom relative to horizontal; and a dial carried on the drum with indicia thereon in amounts to indicate reach of the boom at diiierent angles relative to horizontal, said dial being 'rotatably adjustable relative to the drum to index said adjacent said datum, and means engaging said dial and drum to rotate the dial with the drum after said indexing.

9. An indicating device for visibly indicating distance of reach of a pivoted boom when at diiferent angles of inclination to horizontal, comprisin a support and a drum rotatable on the support; a drive train connecting the drum and pivoted boom for rotating the drum in proportion to swinging of the boom between generally horizontal and upright'positions; an inner dial and an outer dial superposed over the inner dial, said inner dial having plural sets of indicia of boom reach distances arranged in spiral paths on the dial face, said outer dial having a plurality of openings arranged on a similar spiral path to expose one of said sets of indicia at a time, means for rotating said dials relative to each other to expose a set of indicia in said outer dial openings corresponding to the length of the boom; a stationary datum adjacent the face of the dials; and means for indexing said inner and outer dials together relative to said drum to bring the indicia adjacent said datum to correctly indicate boom reach distance.

10. An indicating device as specified in claim 9 in which said inner and outerdials are generally flat resilient plate members and are provided with mating dctents at spaced intervals arranged in a circular pattern for frictionally holding said dials against rotation relative to each other.

11. An indicating device as specified in claim 9 in 'for indicating relatively large change of reach with relatively small boom angle change.

12. An indicator for visibly indicating reach distance and angle of inclination of a pivoted boom in construction machinery and the like, comprising: a support having an outwardly extending shaft; a drum rotatable on said shaft; a drive train connected with said drum to rotate the drum in proportion to swinging movement of boom, said drum having a front wall; a pair of superposed dials supported on said drum against said drum front wall to rotate with the drum, said dials having inner hubs rotatableabout a portion of said drum for angular positioning adjustment of each dial relative to the drum and to each other; a stationary datum adjacent at least a portion of the dials and the periphery of the drum, saiddrum carrying degree indicia swingable past said datum to indicate angular orientation of the boom relative to horizontaLsaid pair of dials each being relatively flat and including an inner dial carrying indicia indicating reach of a plurality of boom lengths, each reach indicia being arranged in a spiral path throughout 360 of the dial about its hub, and said pair of dials including an outer dial With openings therein arranged in a spiral path to expose one of said reach indicia at a time; and means for holding said dials in adjusted position relative to each other and to the drum.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN INDICATOR FOR VISIBLY INDICATING REACH DISTANCE AND ANGLE OF INCLINATION OF A PIVOTED BOOM IN CONSTRUCTION MACHINERY AND THE LIKE, COMPRISING: A ROTATABLE DRUM AND A CABLE DRIVE CONNECTING THE BOOM AND DRUM TO ROTATE THE DRUM IN PROPORTION TO SWINGING OF THE BOOM ABOUT ITS PIVOT; A MOUNTING FOR THE DRUM INCLUDING A STATIONARY DATUM; DEGREE INDICIA ON THE DRUM FOR INDICATING FROM 0* TO 90* OF BOOM SWING FROM HORIZONTAL TO VERTICAL POSITIONS RESPECTIVELY; AND SUPERPOSED DIALS CARRIED BY SAID DRUM FOR ROTATION THEREWITH, ONE DIAL HAVING OPENINGS THEREIN ARRANGED ON A SPIRAL PATH AND THE OTHER DIAL HAVING INDICIA SPACED TO BE EXPOSED IN SAID ONE DIAL OPENINGS IN- 